Reworked launchd support to work better with _xcb_parse_display
Reworked launchd support to work better with _xcb_parse_display

Fixes: http://xquartz.macosforge.org/trac/ticket/390

Signed-off-by: Jeremy Huddleston <db3cec0cba09acb9cf8fd8bd399a3b27498cf883@apple.com>

stapelberg/libxcb,stapelberg/libxcb,stapelberg/libxcb